// 定义圆形
class Circle {
    double radius;
    Circle(double r) {
        radius = r;
    }
    double getArea() {
        return Math.PI * radius * radius;
    }
    double getCircumference() {
        return 2 * Math.PI * radius;
    }
    void setRadius(double newRadius) {
        radius = newRadius;
    }
    double getRadius() {
        return radius;
    }
}
